Japanese Patent Laying-Open No. 11-220807 discloses a mileage indicator for a hybrid vehicle. The mileage indicator calculates a reference fuel economy depending on the vehicle's traveling state, and the mileage indicator indicates a measured fuel economy in comparison with the reference fuel economy.
In recent years a hybrid vehicle allowing its mounted power storage device to be charged from a power supply external thereto is gaining attention. This externally chargeable hybrid vehicle can be externally supplied with two types of energy, i.e., fuel and electric power.
When this type of hybrid vehicle is supplied with energy, whether it should be supplied with both or one of fuel and electric power can be determined by the user of the vehicle, as desired. However, the information available to the user in supplying energy is limited to a unit price of fuel and a unit price of electric power or the like.